feat(browser)!: Extract performance.{mark,measure} spans into new userTimingSpansIntegration

[msonnb]

What?

browserTracingIntegration no longer captures performance.mark() / performance.measure() spans by default. This behavior moves into a new opt-in userTimingSpansIntegration, and the ignorePerformanceApiSpans option is replaced by the integration's ignore option.

// before
Sentry.init({
  integrations: [
    Sentry.browserTracingIntegration({ ignorePerformanceApiSpans: ['third-party-mark'] }),
  ],
});

// after
Sentry.init({
  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.userTimingSpansIntegration({ ignore: ['third-party-mark'] }),
  ],
});

Why?

User Timing spans are useful for some apps and pure noise for others (browser extensions and third-party libraries emit their own mark/measure entries). Bundling them into browserTracingIntegration meant everyone paid the bundle-size and span-volume cost whether they wanted the data or not, and the only escape hatch was an ignore-list. Making it a separate, explicitly-added integration means you opt in when you want it, and it drops out of the tree-shaken bundle when you don't.

Closes #22352

[msonnb]

bugbot run

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	27.95 kB	-	-
@sentry/browser - with treeshaking flags	26.39 kB	-	-
@sentry/browser (incl. Tracing)	46.14 kB	-0.59%	-272 B 🔽
@sentry/browser (incl. Tracing + Span Streaming)	47.87 kB	-0.66%	-316 B 🔽
@sentry/browser (incl. Tracing, Profiling)	50.91 kB	-0.6%	-305 B 🔽
@sentry/browser (incl. Tracing, Replay)	85.38 kB	-0.36%	-306 B 🔽
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	75.04 kB	-0.39%	-290 B 🔽
@sentry/browser (incl. Tracing, Replay with Canvas)	90.1 kB	-0.34%	-304 B 🔽
@sentry/browser (incl. Tracing, Replay, Feedback)	102.74 kB	-0.31%	-317 B 🔽
@sentry/browser (incl. Feedback)	45.13 kB	-	-
@sentry/browser (incl. sendFeedback)	32.74 kB	-	-
@sentry/browser (incl. FeedbackAsync)	37.8 kB	-	-
@sentry/browser (incl. Metrics)	29.04 kB	-	-
@sentry/browser (incl. Logs)	29.26 kB	-	-
@sentry/browser (incl. Metrics & Logs)	29.97 kB	-	-
@sentry/react	29.75 kB	-	-
@sentry/react (incl. Tracing)	48.43 kB	-0.58%	-282 B 🔽
@sentry/vue	33.38 kB	-	-
@sentry/vue (incl. Tracing)	48.1 kB	-0.61%	-294 B 🔽
@sentry/svelte	27.97 kB	-	-
CDN Bundle	30.28 kB	-	-
CDN Bundle (incl. Tracing)	48.38 kB	+0.27%	+126 B 🔺
CDN Bundle (incl. Logs, Metrics)	31.85 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics)	49.71 kB	+0.28%	+134 B 🔺
CDN Bundle (incl. Replay, Logs, Metrics)	71.13 kB	-	-
CDN Bundle (incl. Tracing, Replay)	85.97 kB	+0.17%	+145 B 🔺
CDN Bundle (incl. Tracing, Replay, Logs, Metrics)	87.28 kB	+0.16%	+139 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback)	91.75 kB	+0.17%	+151 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics)	93.06 kB	+0.19%	+170 B 🔺
CDN Bundle - uncompressed	90.15 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	145.57 kB	+0.25%	+357 B 🔺
CDN Bundle (incl. Logs, Metrics) - uncompressed	94.86 kB	-	-
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed	149.56 kB	+0.24%	+357 B 🔺
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed	219.62 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	264.81 kB	+0.14%	+357 B 🔺
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed	268.78 kB	+0.14%	+357 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	278.51 kB	+0.13%	+357 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed	282.47 kB	+0.13%	+357 B 🔺
@sentry/nextjs (client)	50.96 kB	-0.55%	-280 B 🔽
@sentry/sveltekit (client)	46.56 kB	-0.61%	-285 B 🔽
@sentry/core/server	80.05 kB	-	-
@sentry/core/browser	52.01 kB	-	-
@sentry/node	123.14 kB	-0.01%	-1 B 🔽
@sentry/node (incl. diagnostics channel injection)	167.14 kB	-	-
@sentry/node/import (ESM hook with diagnostics-channel injection)	166 B	-	-
@sentry/node - without tracing	73.31 kB	-0.01%	-1 B 🔽
@sentry/aws-serverless	82.82 kB	-	-
@sentry/cloudflare (withSentry) - minified	197.05 kB	-	-
@sentry/cloudflare (withSentry)	484.73 kB	-	-

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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